The use of chemical vapor deposition (CVD) for fabricating light emitting diodes (LEDs) is well known. Chemical vapor deposition is performed in a chamber. Wafers are placed upon a susceptor within the chamber. A vacuum is formed in the chamber. The susceptor rotates the wafers as reactant gases are injected into the chamber.
The reactant gases are applied to the wafers so as to form desired layers of material upon the wafers. Using chemical vapor deposition, layers of positively doped semiconductor and layers of negatively doped semiconductor can be formed upon wafers in a manner that defines the active region of LEDs. Other layers, such as conductive layers, insulator layers, and passivation layers, can also be formed.
The reactant gases can be applied to the wafers via a shower head that is disposed above the susceptor. It is desirable that the reactant gases be applied uniformly across a wafer so as to facilitate the deposition of uniform (in thickness and composition) layers of material upon the wafer. The uniformity with which reactant gases are applied to a wafer depends, at least in part, upon the uniformity of the temperature of the shower head, particularly the lower surface and injectors thereof.
In view of the foregoing, it is desirable to provide a method and system for facilitating enhanced control of reactant gases that are injected into a chemical vapor deposition chamber.